Abstract: In this paper, a new method of measuring the spacecraft magnetic moment is proposed. Firstly, a new spacecraft magnetism model is established in the Gauss expressions. Secondly, based on the characteristics of the model, five groups of induction coils are designed, and the magnetic flux expressions of each magnetic moment components are obtained with related calculation formula. Finally, the error of the approximation produced in the derivation process of the magnetic flux expressions and the theoretical error produced when the integration is used to deal with the measurement data are analyzed. The results indicate that the dynamic loop methods not only can measure the magnetic moment and the magnetic center of spacecraft perfectly, but also has some advantages such as simple measurement process, faster measuring speed and better precision. The error of the approximation is not more than 2% and the theoretical error of integration is 0.17% when the value of L is equal to 5% of the radius of the coil.